Jim Foster, the editor of Diet-Blog.com, told ABCNEWS.com that the failure of a weight loss program's spokesperson is definitely a sign to fellow dieters that perhaps that plan isn't going to work, but added that the spokesperson for a brand is often not someone many people can identify with.
"Right or wrongly, many of us view celebrities as 'privileged' — the ones that can afford personal trainers and home-delivered meals," said Foster. "Because of this, we have a perception that psychical transformation must be easier for them."
"With that said, I'm not sure how many people honestly identify with a celebrity figure. We tend to put them in the 'unreal' category — a source of entertainment rather than inspiration," said Foster.
Carla Wolper, a nutritionist at the Obesity Research Center at St. Luke Hospital in New York, said she doubts the loss of a spokesperson will have much of an effect on anyone.
"Even if someone flunks at a diet, if they're doing well then they're not going to suddenly just quit," said Wolper. "If most people find a method that is successful and they're not having any trouble adhering to the method, it won't matter if the CEO and the spokesperson [leaves the company]."
While dieters like Foster may not care very much about the spokesperson for a particular diet, nutritionists say companies put a great deal of thought into who they have representing their weight loss programs.
"Sometimes people really do care about the spokespeople [of a diet plan]," said Debbie Then, a clinical psychologist who specializes in women's appearance issues. "If they don't like the person to begin with, they may not pay attention to the diet."
"Companies pay a lot of attention to who they name a spokesperson," added Then, who said that her chief complaint with many diets is the lack of acknowledgement of some of the underlying reasons people over-eat and become obese, such as emotional problems.
"Dieters like role models and people who they emulate," said Then. "Initially companies pick people who a wide variety of people can identify with, and I do think it's hard to all of a sudden have that person gone."
There has never been a scientific study that compares the success of programs like Jenny Craig with and without a recognizable spokesperson, but Yale's Katz said spokespeople are undoubtedly a large investment for companies.
"We know that big companies with deep pockets routinely use celebrities to endorse," said Katz. "Clearly the value of a celebrity to represent your product is well established."
"But if you have a high-profile spokesperson on your diet plan and they're gaining weight, that's not good for business."